1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)ufs.c 8.1 (Berkeley) 6/11/93 37 * 38 * 39 * Copyright (c) 1990, 1991 Carnegie Mellon University 40 * All Rights Reserved. 41 * 42 * Author: David Golub 43 * 44 * Permission to use, copy, modify and distribute this software and its 45 * documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 52 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 * 64 * $Id: ufs.c,v 1.7 1994/08/22 21:56:15 brezak Exp $ 65 */ 66 67 /* 68 * Stand-alone file reading package. 69 */ 70 71 #include <string.h> 72 #include <sys/param.h> 73 #include <sys/time.h> 74 #include <ufs/ffs/fs.h> 75 #include <ufs/ufs/dinode.h> 76 #include <ufs/ufs/dir.h> 77 #include <lib/libkern/libkern.h> 78 79 #include "stand.h" 80 81 /* 82 * In-core open file. 83 */ 84 struct file { 85 off_t f_seekp; /* seek pointer */ 86 struct fs *f_fs; /* pointer to super-block */ 87 struct dinode f_di; /* copy of on-disk inode */ 88 int f_nindir[NIADDR]; 89 /* number of blocks mapped by 90 indirect block at level i */ 91 char *f_blk[NIADDR]; /* buffer for indirect block at 92 level i */ 93 u_long f_blksize[NIADDR]; 94 /* size of buffer */ 95 daddr_t f_blkno[NIADDR];/* disk address of block in buffer */ 96 char *f_buf; /* buffer for data block */ 97 u_int f_buf_size; /* size of data block */ 98 daddr_t f_buf_blkno; /* block number of data block */ 99 }; 100 101 #ifdef COMPAT_UFS 102 void ffs_oldfscompat __P((struct fs *)); 103 #endif 104 105 /* 106 * Read a new inode into a file structure. 107 */ 108 static int 109 read_inode(inumber, f) 110 ino_t inumber; 111 struct open_file *f; 112 { 113 register struct file *fp = (struct file *)f->f_fsdata; 114 register struct fs *fs = fp->f_fs; 115 char *buf; 116 u_int rsize; 117 int rc; 118 119 /* 120 * Read inode and save it. 121 */ 122 buf = alloc(fs->fs_bsize); 123 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ, 124 fsbtodb(fs, ino_to_fsba(fs, inumber)), fs->fs_bsize, buf, &rsize); 125 if (rc) 126 goto out; 127 if (rsize != fs->fs_bsize) { 128 rc = EIO; 129 goto out; 130 } 131 132 { 133 register struct dinode *dp; 134 135 dp = (struct dinode *)buf; 136 fp->f_di = dp[ino_to_fsbo(fs, inumber)]; 137 } 138 139 /* 140 * Clear out the old buffers 141 */ 142 { 143 register int level; 144 145 for (level = 0; level < NIADDR; level++) 146 fp->f_blkno[level] = -1; 147 fp->f_buf_blkno = -1; 148 } 149 out: 150 free(buf, fs->fs_bsize); 151 return (0); 152 } 153 154 /* 155 * Given an offset in a file, find the disk block number that 156 * contains that block. 157 */ 158 static int 159 block_map(f, file_block, disk_block_p) 160 struct open_file *f; 161 daddr_t file_block; 162 daddr_t *disk_block_p; /* out */ 163 { 164 register struct file *fp = (struct file *)f->f_fsdata; 165 register struct fs *fs = fp->f_fs; 166 int level; 167 int idx; 168 daddr_t ind_block_num; 169 daddr_t *ind_p; 170 int rc; 171 172 /* 173 * Index structure of an inode: 174 * 175 * di_db[0..NDADDR-1] hold block numbers for blocks 176 * 0..NDADDR-1 177 * 178 * di_ib[0] index block 0 is the single indirect block 179 * holds block numbers for blocks 180 * NDADDR .. NDADDR + NINDIR(fs)-1 181 * 182 * di_ib[1] index block 1 is the double indirect block 183 * holds block numbers for INDEX blocks for blocks 184 * NDADDR + NINDIR(fs) .. 185 * NDADDR + NINDIR(fs) + NINDIR(fs)**2 - 1 186 * 187 * di_ib[2] index block 2 is the triple indirect block 188 * holds block numbers for double-indirect 189 * blocks for blocks 190 * NDADDR + NINDIR(fs) + NINDIR(fs)**2 .. 191 * NDADDR + NINDIR(fs) + NINDIR(fs)**2 192 * + NINDIR(fs)**3 - 1 193 */ 194 195 if (file_block < NDADDR) { 196 /* Direct block. */ 197 *disk_block_p = fp->f_di.di_db[file_block]; 198 return (0); 199 } 200 201 file_block -= NDADDR; 202 203 /* 204 * nindir[0] = NINDIR 205 * nindir[1] = NINDIR**2 206 * nindir[2] = NINDIR**3 207 * etc 208 */ 209 for (level = 0; level < NIADDR; level++) { 210 if (file_block < fp->f_nindir[level]) 211 break; 212 file_block -= fp->f_nindir[level]; 213 } 214 if (level == NIADDR) { 215 /* Block number too high */ 216 return (EFBIG); 217 } 218 219 ind_block_num = fp->f_di.di_ib[level]; 220 221 for (; level >= 0; level--) { 222 if (ind_block_num == 0) { 223 *disk_block_p = 0; /* missing */ 224 return (0); 225 } 226 227 if (fp->f_blkno[level] != ind_block_num) { 228 if (fp->f_blk[level] == (char *)0) 229 fp->f_blk[level] = 230 alloc(fs->fs_bsize); 231 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ, 232 fsbtodb(fp->f_fs, ind_block_num), 233 fs->fs_bsize, 234 fp->f_blk[level], 235 (u_int *)&fp->f_blksize[level]); 236 if (rc) 237 return (rc); 238 if (fp->f_blksize[level] != fs->fs_bsize) 239 return (EIO); 240 fp->f_blkno[level] = ind_block_num; 241 } 242 243 ind_p = (daddr_t *)fp->f_blk[level]; 244 245 if (level > 0) { 246 idx = file_block / fp->f_nindir[level - 1]; 247 file_block %= fp->f_nindir[level - 1]; 248 } else 249 idx = file_block; 250 251 ind_block_num = ind_p[idx]; 252 } 253 254 *disk_block_p = ind_block_num; 255 256 return (0); 257 } 258 259 /* 260 * Read a portion of a file into an internal buffer. Return 261 * the location in the buffer and the amount in the buffer. 262 */ 263 static int 264 buf_read_file(f, buf_p, size_p) 265 struct open_file *f; 266 char **buf_p; /* out */ 267 u_int *size_p; /* out */ 268 { 269 register struct file *fp = (struct file *)f->f_fsdata; 270 register struct fs *fs = fp->f_fs; 271 long off; 272 register daddr_t file_block; 273 daddr_t disk_block; 274 long block_size; 275 int rc; 276 277 off = blkoff(fs, fp->f_seekp); 278 file_block = lblkno(fs, fp->f_seekp); 279 block_size = dblksize(fs, &fp->f_di, file_block); 280 281 if (file_block != fp->f_buf_blkno) { 282 rc = block_map(f, file_block, &disk_block); 283 if (rc) 284 return (rc); 285 286 if (fp->f_buf == (char *)0) 287 fp->f_buf = alloc(fs->fs_bsize); 288 289 if (disk_block == 0) { 290 bzero(fp->f_buf, block_size); 291 fp->f_buf_size = block_size; 292 } else { 293 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ, 294 fsbtodb(fs, disk_block), 295 block_size, fp->f_buf, &fp->f_buf_size); 296 if (rc) 297 return (rc); 298 } 299 300 fp->f_buf_blkno = file_block; 301 } 302 303 /* 304 * Return address of byte in buffer corresponding to 305 * offset, and size of remainder of buffer after that 306 * byte. 307 */ 308 *buf_p = fp->f_buf + off; 309 *size_p = block_size - off; 310 311 /* 312 * But truncate buffer at end of file. 313 */ 314 if (*size_p > fp->f_di.di_size - fp->f_seekp) 315 *size_p = fp->f_di.di_size - fp->f_seekp; 316 317 return (0); 318 } 319 320 /* 321 * Search a directory for a name and return its 322 * i_number. 323 */ 324 static int 325 search_directory(name, f, inumber_p) 326 char *name; 327 struct open_file *f; 328 ino_t *inumber_p; /* out */ 329 { 330 register struct file *fp = (struct file *)f->f_fsdata; 331 register struct direct *dp; 332 struct direct *edp; 333 char *buf; 334 u_int buf_size; 335 int namlen, length; 336 int rc; 337 338 length = strlen(name); 339 340 fp->f_seekp = 0; 341 while (fp->f_seekp < fp->f_di.di_size) { 342 rc = buf_read_file(f, &buf, &buf_size); 343 if (rc) 344 return (rc); 345 346 dp = (struct direct *)buf; 347 edp = (struct direct *)(buf + buf_size); 348 while (dp < edp) { 349 if (dp->d_ino == (ino_t)0) 350 goto next; 351 #if BYTE_ORDER == LITTLE_ENDIAN 352 if (fp->f_fs->fs_maxsymlinklen <= 0) 353 namlen = dp->d_type; 354 else 355 #endif 356 namlen = dp->d_namlen; 357 if (namlen == length && 358 !strcmp(name, dp->d_name)) { 359 /* found entry */ 360 *inumber_p = dp->d_ino; 361 return (0); 362 } 363 next: 364 dp = (struct direct *)((char *)dp + dp->d_reclen); 365 } 366 fp->f_seekp += buf_size; 367 } 368 return (ENOENT); 369 } 370 371 /* 372 * Open a file. 373 */ 374 int 375 ufs_open(path, f) 376 char *path; 377 struct open_file *f; 378 { 379 register char *cp, *ncp; 380 register int c; 381 ino_t inumber, parent_inumber; 382 struct file *fp; 383 struct fs *fs; 384 int rc; 385 u_int buf_size; 386 #if 0 387 int nlinks = 0; 388 char namebuf[MAXPATHLEN+1]; 389 #endif 390 391 /* allocate file system specific data structure */ 392 fp = alloc(sizeof(struct file)); 393 bzero(fp, sizeof(struct file)); 394 f->f_fsdata = (void *)fp; 395 396 /* allocate space and read super block */ 397 fs = alloc(SBSIZE); 398 fp->f_fs = fs; 399 rc = (f->f_dev->dv_strategy)(f->f_devdata, F_READ, 400 SBLOCK, SBSIZE, (char *)fs, &buf_size); 401 if (rc) 402 goto out; 403 404 if (buf_size != SBSIZE || fs->fs_magic != FS_MAGIC || 405 fs->fs_bsize > MAXBSIZE || fs->fs_bsize < sizeof(struct fs)) { 406 rc = EINVAL; 407 goto out; 408 } 409 #ifdef COMPAT_UFS 410 ffs_oldfscompat(fs); 411 #endif 412 413 /* 414 * Calculate indirect block levels. 415 */ 416 { 417 register int mult; 418 register int level; 419 420 mult = 1; 421 for (level = 0; level < NIADDR; level++) { 422 mult *= NINDIR(fs); 423 fp->f_nindir[level] = mult; 424 } 425 } 426 427 inumber = ROOTINO; 428 if ((rc = read_inode(inumber, f)) != 0) 429 goto out; 430 431 cp = path; 432 while (*cp) { 433 434 /* 435 * Remove extra separators 436 */ 437 while (*cp == '/') 438 cp++; 439 if (*cp == '\0') 440 break; 441 442 /* 443 * Check that current node is a directory. 444 */ 445 if ((fp->f_di.di_mode & IFMT) != IFDIR) { 446 rc = ENOTDIR; 447 goto out; 448 } 449 450 /* 451 * Get next component of path name. 452 */ 453 { 454 register int len = 0; 455 456 ncp = cp; 457 while ((c = *cp) != '\0' && c != '/') { 458 if (++len > MAXNAMLEN) { 459 rc = ENOENT; 460 goto out; 461 } 462 cp++; 463 } 464 *cp = '\0'; 465 } 466 467 /* 468 * Look up component in current directory. 469 * Save directory inumber in case we find a 470 * symbolic link. 471 */ 472 parent_inumber = inumber; 473 rc = search_directory(ncp, f, &inumber); 474 *cp = c; 475 if (rc) 476 goto out; 477 478 /* 479 * Open next component. 480 */ 481 if ((rc = read_inode(inumber, f)) != 0) 482 goto out; 483 484 #if 0 485 /* 486 * Check for symbolic link. 487 */ 488 if ((fp->i_mode & IFMT) == IFLNK) { 489 int link_len = fp->f_di.di_size; 490 int len; 491 492 len = strlen(cp) + 1; 493 494 if (fp->f_di.di_size >= MAXPATHLEN - 1 || 495 ++nlinks > MAXSYMLINKS) { 496 rc = ENOENT; 497 goto out; 498 } 499 500 strcpy(&namebuf[link_len], cp); 501 502 if ((fp->i_flags & IC_FASTLINK) != 0) { 503 bcopy(fp->i_symlink, namebuf, (unsigned) link_len); 504 } else { 505 /* 506 * Read file for symbolic link 507 */ 508 char *buf; 509 u_int buf_size; 510 daddr_t disk_block; 511 register struct fs *fs = fp->f_fs; 512 513 (void) block_map(f, (daddr_t)0, &disk_block); 514 rc = device_read(&fp->f_dev, 515 fsbtodb(fs, disk_block), 516 blksize(fs, fp, 0), 517 &buf, &buf_size); 518 if (rc) 519 goto out; 520 521 bcopy((char *)buf, namebuf, (unsigned)link_len); 522 free(buf, buf_size); 523 } 524 525 /* 526 * If relative pathname, restart at parent directory. 527 * If absolute pathname, restart at root. 528 */ 529 cp = namebuf; 530 if (*cp != '/') 531 inumber = parent_inumber; 532 else 533 inumber = (ino_t)ROOTINO; 534 535 if ((rc = read_inode(inumber, fp)) != 0) 536 goto out; 537 } 538 #endif 539 } 540 541 /* 542 * Found terminal component. 543 */ 544 rc = 0; 545 out: 546 if (rc) 547 free(fp, sizeof(struct file)); 548 return (rc); 549 } 550 551 int 552 ufs_close(f) 553 struct open_file *f; 554 { 555 register struct file *fp = (struct file *)f->f_fsdata; 556 int level; 557 558 f->f_fsdata = (void *)0; 559 if (fp == (struct file *)0) 560 return (0); 561 562 for (level = 0; level < NIADDR; level++) { 563 if (fp->f_blk[level]) 564 free(fp->f_blk[level], fp->f_fs->fs_bsize); 565 } 566 if (fp->f_buf) 567 free(fp->f_buf, fp->f_fs->fs_bsize); 568 free(fp->f_fs, SBSIZE); 569 free(fp, sizeof(struct file)); 570 return (0); 571 } 572 573 /* 574 * Copy a portion of a file into kernel memory. 575 * Cross block boundaries when necessary. 576 */ 577 int 578 ufs_read(f, start, size, resid) 579 struct open_file *f; 580 char *start; 581 u_int size; 582 u_int *resid; /* out */ 583 { 584 register struct file *fp = (struct file *)f->f_fsdata; 585 register u_int csize; 586 char *buf; 587 u_int buf_size; 588 int rc = 0; 589 590 while (size != 0) { 591 if (fp->f_seekp >= fp->f_di.di_size) 592 break; 593 594 rc = buf_read_file(f, &buf, &buf_size); 595 if (rc) 596 break; 597 598 csize = size; 599 if (csize > buf_size) 600 csize = buf_size; 601 602 bcopy(buf, start, csize); 603 604 fp->f_seekp += csize; 605 start += csize; 606 size -= csize; 607 } 608 if (resid) 609 *resid = size; 610 return (rc); 611 } 612 613 /* 614 * Not implemented. 615 */ 616 int 617 ufs_write(f, start, size, resid) 618 struct open_file *f; 619 char *start; 620 u_int size; 621 u_int *resid; /* out */ 622 { 623 624 return (EROFS); 625 } 626 627 off_t 628 ufs_seek(f, offset, where) 629 struct open_file *f; 630 off_t offset; 631 int where; 632 { 633 register struct file *fp = (struct file *)f->f_fsdata; 634 635 switch (where) { 636 case SEEK_SET: 637 fp->f_seekp = offset; 638 break; 639 case SEEK_CUR: 640 fp->f_seekp += offset; 641 break; 642 case SEEK_END: 643 fp->f_seekp = fp->f_di.di_size - offset; 644 break; 645 default: 646 return (-1); 647 } 648 return (fp->f_seekp); 649 } 650 651 int 652 ufs_stat(f, sb) 653 struct open_file *f; 654 struct stat *sb; 655 { 656 register struct file *fp = (struct file *)f->f_fsdata; 657 658 /* only important stuff */ 659 sb->st_mode = fp->f_di.di_mode; 660 sb->st_uid = fp->f_di.di_uid; 661 sb->st_gid = fp->f_di.di_gid; 662 sb->st_size = fp->f_di.di_size; 663 return (0); 664 } 665 666 #ifdef COMPAT_UFS 667 /* 668 * Sanity checks for old file systems. 669 * 670 * XXX - goes away some day. 671 */ 672 void 673 ffs_oldfscompat(fs) 674 struct fs *fs; 675 { 676 int i; 677 678 fs->fs_npsect = max(fs->fs_npsect, fs->fs_nsect); /* XXX */ 679 fs->fs_interleave = max(fs->fs_interleave, 1); /* XXX */ 680 if (fs->fs_postblformat == FS_42POSTBLFMT) /* XXX */ 681 fs->fs_nrpos = 8; /* XXX */ 682 if (fs->fs_inodefmt < FS_44INODEFMT) { /* XXX */ 683 quad_t sizepb = fs->fs_bsize; /* XXX */ 684 /* XXX */ 685 fs->fs_maxfilesize = fs->fs_bsize * NDADDR - 1; /* XXX */ 686 for (i = 0; i < NIADDR; i++) { /* XXX */ 687 sizepb *= NINDIR(fs); /* XXX */ 688 fs->fs_maxfilesize += sizepb; /* XXX */ 689 } /* XXX */ 690 fs->fs_qbmask = ~fs->fs_bmask; /* XXX */ 691 fs->fs_qfmask = ~fs->fs_fmask; /* XXX */ 692 } /* XXX */ 693 } 694 #endif 695